1. Field of the Invention
The present invention relates to the field of telecommunications. More particularly, the present invention relates to a method and a system for transferring digital data calls between different destinations.
2. Description of the Related Art
A basic "toll-free" 800 number call is a simple one-to-one transaction from a traditional POTS terminal, from which an 8YY (i.e., 800 or 888) number is dialed, to a traditional POTS destination telephone number having an associated reverse-billing capacity. Voice network services have evolved so that a toll-free 8YY call can be directed to different destinations based on, for example, a time of day, an originating NPA (Number Plan Area), basic information about a caller, a location of a calling party, additional digits collected from a calling party, availability and preferences of a called party, as well as such items as call forwarding options when a busy signal is obtained.
New forms of digital communications services that use digital technologies requiring end-to-end digital facilities have been introduced into the telephone networks, in contrast to the voice band (POTS) services that are required by voice calls. As a consequence, telephone service, specifically toll-free 8YY service, referred to herein as toll-free 800 service, has evolved so that data calls to a particular 800 number are routed to one destination providing end-to-end data communications services, while voice calls to the same toll-free 800 number are routed to another destination providing voice communications services. Data calls, as used herein, refer to digital communication services calls. Digital services send data calls on digital facility network lines, such as over 56/64 Kbps data lines, for transferring data for multimedia purposes, file and image transfer, slow scan video and numerous other data transfer requirements. Voice calls, as used herein, refer to all forms of voiceband services carried over a POTS network.
U.S. Pat. No. 5,533,108 to Harris et al., incorporated by reference herein, discloses an 800 multimedia system for routing phone calls to a common telephone number, such as a toll-free 800 telephone number, to a selected destination based on whether the call is a voice call or a data call. The Harris et al. system also has the capability of routing each data call based on a requested data rate and the handling capabilities required for completing and servicing the call. Consequently, a toll-free 800 number subscriber, such as a mail-order service, can use a single 800 number for providing both voice service capability and end-to-end data service capability for soliciting catalog orders. Voice calls are routed to a regular voice agent, while data calls are routed to a video agent for providing a caller with visual representations of products and other order information. A Direct Services Dialing (DSD) database is accessed in response to a voice call to the common number for providing an appropriate destination number for serving the voice call based on common call discriminators. A destination number for a data call, which may be different from the destination for a voice call, is also obtained from the DSD database based jointly on the common discriminators and a requested data rate discriminator. The destination number for a data call can vary based on the requested data rate discriminator so that data calls having different data rates are routed through appropriate data networks to a destination having the correct data rate capability.
For example, a hotel reservation system can provide both voice and data services at a single toll-free 800 number for making reservations and arrangements for other services provided by the hotel. In a conventional system, such as the system disclosed by Harris et al., a voice call can be extended from its initial destination so that a caller can be conveniently transferred, from the point of view of the caller, to another destination, such as to a car rental agency. An adjunct platform, referred to as a VP, that operates on a tandem toll switch, such as a 4ESS.TM. type switch, provides the capability of transferring a voice call that has been initially routed through the switch to another destination. When the VP adjunct receives a predetermined DTMF tone or sequence of DTMF tones from the first destination, followed by a 10-digit number for the next destination, the line to the initial destination is terminated and the call is transferred to the next destination. By transferring the voice call at the 4ESS.TM. switch, the line to the first destination is made available to another call to the destination.
Presently, data service has the capability of extending a call to a second destination, but there is not a way to transfer a data call to other destination. When a data call is extended to a second destination, the incoming line to the first destination used by the data call remains seized and the subscriber at the first destination pays for the call for the duration the call is extended. Additionally, as long as the line is seized, no additional calls can be completed to the subscriber on that line.
What is needed is a way to transfer a data call to another destination. Further, as Web-based applications evolve, the need for additional data bandwidth, such as ISDN speeds of switched 56, 64, 384 and 1536 Kbps, is increasing. Along with the need for additional bandwidth, a secure way to conduct electronic commerce on the Internet is also needed.